I'm trying to understand if there is a certain protocol that a Wi-Fi transmitter must follow when creating a BSSID for virtual access points.
In my university building, there are a bunch of CISCO routers and each provide 2 virtual access points: "eduroam" and "wifi guest". The BSSIDs for one Wi-Fi transmitter are 58:97:bd:4a:d6:70 and 58:97:bd:4a:d6:76. Based on this example, it looks like only the last 2 characters of the BSSID are unique, and I presume that the first 10 are part of the original MAC address of the Wi-Fi transmitter.
Does anyone know if there is a certain protocol which must be followed when creating a virtual access point? Or does the CISCO Wi-Fi transmitter have it's own unique methodology of creating these? Specifically, I'm looking for a citable source for this.